# Topics in Physics

سه شنبه 21 خرداد 1392

It is strange for me that the uncertainty in the measurement of the neutron lifetime is still large (larger than 0.1 % level)! The following takes advantage of this relatively large uncertainty:

Deficit of reactor antineutrinos at distances smaller than 100 m and inverse beta-decay
Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex); Nuclear Theory (nucl-th)

We analyse a change of a deficit of reactor antineutrinos at distances smaller than 100 m by changing the lifetime of the neutron from tau_n = 885.7 s to tau_n = 879.6 s, calculated for the axial coupling constants lambda = - 1.2694 and lambda = - 1.2750, respectively, in order to get a result corresponding the new world average value tau_n = 880.1(1.1) s. We calculate the angular distribution and cross section for the inverse beta-decay, taking into account the contributions of the "weak magnetism" and the neutron recoil to next-to-leading order in the large baryon mass expansion and the radiative corrections of order alpha/\pi ~ 10^(-3), calculated to leading order in the large baryon mass expansion. We obtain an increase of a deficit of reactor antineutrinos in of about 0.734%.

 بؤلوم : یازار : Yasaman Farzan